1. Field of the Invention
The present invention relates generally to electrical systems. The present invention relates more particularly to electrical wiring systems suitable for use in roofing applications.
2. Technical Background
The search for alternative sources of energy has been motivated by at least two factors. First, fossil fuels have become increasingly expensive due to increasing scarcity and unrest in areas rich in petroleum deposits. Second, there exists overwhelming concern about the effects of the combustion of fossil fuels on the environment due to factors such as air pollution (from NOx, hydrocarbons and ozone) and global warming (from CO2). Moreover, the very discovery and exploitation of fossil fuels carries significant environmental risk. In recent years, research and development attention has focused on harvesting energy from natural environmental sources such as wind, flowing water, and the sun. Of the three, the sun appears to be the most widely useful energy source across the continental United States; most locales get enough sunshine to make solar energy feasible.
Accordingly, there are now available components that convert light energy into electrical energy. Such photovoltaic elements are often made from semiconductor-type materials such as doped silicon in either single crystalline, polycrystalline, or amorphous form. The use of photovoltaic elements on roofs is becoming increasingly common, especially as device performance has improved. They can be used to provide at least a significant fraction of the electrical energy needed for a building's overall function; or they can be used to power one or more particular devices, such as exterior lighting systems.
Often perched on an existing roof in panel form, these photovoltaic elements can often be quite visible and generally not aesthetically pleasant. Moreover, the electrical cables used to interconnect the photovoltaic elements can be another source of aesthetic dissonance. Nonetheless, to date, installations have appeared to have been motivated by purely practical and functional considerations; there appears to have been little coordination between the appearance of the photovoltaic system and the roofing materials (e.g., tiles or shingles) and buildings upon which they are mounted. Lack of aesthetic appeal is especially problematic in residential buildings with non-horizontally pitched roofs; people tend to put a much higher premium on the appearance of their homes than they do on the appearance of their commercial buildings.
Accordingly, there remains a need for photovoltaic systems having more controllable and desirable aesthetics for use in roofing applications while retaining sufficient efficiency in electrical power generation, and for aesthetically appropriate building elements for use with photovoltaic systems.